Speed up CV_Findvar & CV_FindNetVar with hashtable

src/command.c

@@ -1443,6 +1443,39 @@ void VS_Print(vsbuf_t *buf, const char *data)
 //
 // =========================================================================
 
+#define NAME      cvar_map_t
+#define KEY_TY    const char *
+#define VAL_TY    consvar_t *
+#define HASH_FN   vt_hash_string
+#define CMPR_FN   vt_cmpr_string
+#include "verstable.h"
+
+#define NAME      netvar_map_t
+#define KEY_TY    UINT16
+#define VAL_TY    consvar_t *
+#define HASH_FN   vt_hash_integer
+#define CMPR_FN   vt_cmpr_integer
+#include "verstable.h"
+
+static cvar_map_t cvar_map;
+static netvar_map_t netvar_map;
+
+CONSTRUCTOR static void CV_InitMap(void)
+{
+	// ensure the map is initialized
+	cvar_map_t_init(&cvar_map);
+	cvar_map_t_reserve(&cvar_map, 512);
+
+	netvar_map_t_init(&netvar_map);
+	netvar_map_t_reserve(&netvar_map, 256);
+}
+
+DESTRUCTOR static void CV_DestroyMap(void)
+{
+	cvar_map_t_cleanup(&cvar_map);
+	netvar_map_t_cleanup(&netvar_map);
+}
+
 static const char *cv_null_string = "";
 
 /** Searches if a variable has been registered.
@@ -1453,11 +1486,17 @@ static const char *cv_null_string = "";
   */
 consvar_t *CV_FindVar(const char *name)
 {
-	consvar_t *cvar;
+	cvar_map_t_itr it = cvar_map_t_get(&cvar_map, name);
+	if (!cvar_map_t_is_end(it))
+		return it.data->val;
 
+	// fallback linear search
+	/*
+	consvar_t *cvar;
 	for (cvar = consvar_vars; cvar; cvar = cvar->next)
 		if (fasticmp(name, cvar->name))
 			return cvar;
+	*/
 
 	return NULL;
 }
@@ -1484,6 +1523,10 @@ static inline UINT16 CV_ComputeLegacyNetid(const char *s)
   */
 static consvar_t *CV_FindNetVar(UINT16 netid)
 {
+	netvar_map_t_itr it = netvar_map_t_get(&netvar_map, netid);
+	if (!netvar_map_t_is_end(it))
+		return it.data->val;
+	/*
 	consvar_t *cvar;
 
 	if (netid > consvar_number_of_netids)
@@ -1492,6 +1535,7 @@ static consvar_t *CV_FindNetVar(UINT16 netid)
 	for (cvar = consvar_vars; cvar; cvar = cvar->next)
 		if (cvar->netid == netid)
 			return cvar;
+	*/
 
 	if (netid == 44542) // ouch this hack
 		return &cv_karteliminatelast;
@@ -1585,6 +1629,11 @@ void CV_RegisterVar(consvar_t *variable)
 
 	// the SetValue will set this bit
 	variable->flags &= ~CV_MODIFIED;
+
+	cvar_map_t_insert(&cvar_map, variable->name, variable);
+
+	if (variable->flags & CV_NETVAR)
+		netvar_map_t_insert(&netvar_map, variable->netid, variable);
 }
 
 /** Finds the string value of a console variable.
@@ -1971,6 +2020,25 @@ static void CV_LoadVars(UINT8 **p,
 	// prevent "invalid command received"
 	serverloading = true;
 
+	// we can use our netvar map instead of going through all cvars each time
+	netvar_map_t_itr it;
+	for (it = netvar_map_t_first(&netvar_map);
+		 !netvar_map_t_is_end(it);
+		 it = netvar_map_t_next(it))
+	{
+		cvar = it.data->val;
+
+		if (store && cvar->revert.v.string == NULL)
+		{
+			cvar->revert.v.const_munge = cvar->string;
+			cvar->revert.allocated = ( cvar->zstring != NULL );
+			cvar->zstring = NULL; // don't free this
+		}
+
+		Setvalue(cvar, cvar->defaultvalue, true);
+	}
+
+	/*
 	for (cvar = consvar_vars; cvar; cvar = cvar->next)
 	{
 		if (cvar->flags & CV_NETVAR)
@@ -1979,12 +2047,12 @@ static void CV_LoadVars(UINT8 **p,
 			{
 				cvar->revert.v.const_munge = cvar->string;
 				cvar->revert.allocated = ( cvar->zstring != NULL );
-				cvar->zstring = NULL;/* don't free this */
+				cvar->zstring = NULL; // don't free this
 			}
 
 			Setvalue(cvar, cvar->defaultvalue, true);
 		}
-	}
+	}*/
 
 	if (got == NULL)
 		G_LoadDemoCvars((void **)p, Setvalue);

src/doomdef.h

@@ -440,6 +440,13 @@ INT32 I_GetKey(void);
 // NOTE: you WILL have nasal troubles if the variable is not initialized
 #define CLEANUP(f) __attribute__((__cleanup__(f)))
 
+// the GNU constructor and destructor attributes
+// The constructor attribute causes the function to be called automatically before execution enters main ().
+// Similarly, the destructor attribute causes the function to be called automatically after main () has completed or exit () has been called.
+// Functions with these attributes are useful for initializing data that will be used implicitly during the execution of the program.
+#define CONSTRUCTOR __attribute__((constructor, used))
+#define DESTRUCTOR __attribute__((destructor, used))
+
 // An assert-type mechanism.
 // NOTE: USE SRB2_ASSERT FOR C++ CODE INSTEAD
 #ifdef PARANOIA

src/sdl/i_system.cpp

@@ -1364,7 +1364,6 @@ static void I_Fork(void)
 INT32 I_StartupSystem(void)
 {
 	int SDLlinked = SDL_GetVersion();
-	W_Startup();
 	I_StartupConsole();
 #ifdef NEWSIGNALHANDLER
 	// This is useful when debugging. It lets GDB attach to

src/w_wad.c

@@ -155,8 +155,7 @@ void W_Shutdown(void)
 }
 
 // the lumpnum cache needs to be initialized before use
-// call this as early as possible!
+CONSTRUCTOR static void W_Startup(void)
-void W_Startup(void)
 {
 	lumpnum_map_init(&lumpnumcache);
 	lumpnum_map_reserve(&lumpnumcache, LUMPNUMCACHESIZE);

src/w_wad.h

@@ -152,7 +152,6 @@ extern wadfile_t *wadfiles[MAX_WADFILES];
 
 // =========================================================================
 
-void W_Startup(void);
 void W_Shutdown(void);
 
 // Opens a WAD file. Returns the FILE * handle for the file, or NULL if not found or could not be opened